Might be kind of an odd question, but....

I'm doing some work on a friends 89 F-150 that's equipped
pretty much like my Bronco (5.8 liter, C-6, etc).
Sometime in the past, he was having driveability problems and swapped out the computer with another one from a salvage yard - he said it was from a truck equpped the same has his.

The question is this - are the computers specific to an individual vehicle, to a group of vehicles (similarly equipped), or can his
performance be improved by switching to a different computer-
say something from a Lightning? And if they are vehicle specific,
what/where are the indicators for the vehicle?

I haven't got a clue what to tell this guy....

msautry

 

Wouldn't use the lightning computer. Should you find one, no telling what they might charge for it and your not gonna see any real gain, if any. I believe over all, based on swaps from 5.0efi to 5.8efi using the same computer there isn't a real difference to take note of. You may suggest to your friend to have a chip reflashed/ burnt for his combination. Good luck

 

There are quite a few different designations on the computers, but the timing and fuel curves are relatively the same. The lightning computer also includes control for an electronic automatic, so it would turn on the CEL with a C6. Generally all truck computers will deliver similar performance characteristics - so similar you will probably never tell a difference. If you have to replace the computer, the truck must be similarly equipped - if it's an automatic, it needs an automatic computer, electronic or non electronic, and needs a computer from a manual if the truck is stick shift. Engine configuration might not matter quite as much, but if you are getting a new one, may as well be for the same engine. Only time I can see running a computer for a different engine is in the case of an engine swap where the same electronics are used from the old engine. The 5.0 and 5.8 might work on either, but you won't get a computer from a 7.5 to run a 4.9 or a 4.9 to run anything other than that, or a 7.5 to run anything else either.

That said, in my '87 I swapped in a mass - air system using a mustang computer, and I can tell a big difference in how the truck performs. I think that the 87 truck computer was rather conservative being that it was the first year for multipoint EFI. It had several quirks about it that the new computer doesn't show at all. But, that's going to a mustang computer which is programmed much hotter than the truck computer anyway. I have no idea what swapping in a computer from a newer truck would do, or if it would do anything at all.